Foley catheters are believed to be almost always made of either natural rubber (latex) or silicone rubber. Because of the different properties of these two compounds, standard manufacturing techniques currently believed to be used for each are somewhat different. Because the present invention is an improvement over these techniques, a description of each follows hereinbelow.
First, however, a short discussion of the products that are formed by these processes is presented as a foundation to clarify the advantages of the present invention. To this end, the Applicants note that silicone rubber catheters are considered to be superior to latex catheters because silicone rubber is believed to be more biocompatible. Studies suggest that silicone rubber catheters cause less adjacent cell death, are less likely to become encrusted, thereby minimizing resulting blockage and/or trauma upon withdrawal, and are more resistant to bacterial colonization. Silicone rubber is also more expensive than natural rubber, however, and, as will be explained below, the standard manufacturing process for silicone catheters has, heretofore, been more labor intensive and, therefore, more costly than the standard manufacturing process for latex catheters. As a result, silicone catheters are generally more expensive than latex catheters and, although believed to be medically superior, are not as widely used as the less expensive latex catheters.
The manufacturing processes of the present invention, which are disclosed and claimed hereinbelow, will allow silicone catheters produced using these processes to be price competitive with the latex catheters, and also provides for certain design advantages over currently available silicone catheters. In order to appreciate the simplicity of the present invention, however, the discussion of the standard manufacturing techniques used to produce the balloon portion of latex and silicone rubber Foley catheters is now presented below.